<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // key 键名
        // value 键值

        // 对象 
        var obj = {
            name:'laowang',
            age:18,
            sex:"男"
        }

        console.log(Object.keys(obj)); //['name', 'age', 'sex']

    </script>
</body>
</html>